Bug in matching algorithm fixed

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

src/mtrie.cpp

@@ -210,13 +210,17 @@ void zmq::mtrie_t::match (unsigned char *data_, size_t size_,
     void (*func_) (pipe_t *pipe_, void *arg_), void *arg_)
 {
     mtrie_t *current = this;
-    while (size_) {
+    while (true) {
 
         //  Signal the pipes attached to this node.
         for (pipes_t::iterator it = current->pipes.begin ();
               it != current->pipes.end (); ++it)
             func_ (*it, arg_);
 
+        //  If we are at the end of the message, there's nothing more to match.
+        if (!size_)
+            break;
+
         //  If there are no subnodes in the trie, return.
         if (current->count == 0)
             break;